1. Field of the Art
This invention relates to a disc texturing apparatus, and more particularly to an apparatus for texturing surfaces of a magnetic disk or similar data storage medium of annular shape with fine intersecting grooves while the disk is put in rotation on a spindle of a rotational drive mechanism.
2. Prior Art
It has been the usual practice in the art to form fine grooves on the surface of a magnetic disk or similarly annular magnetic data storage medium by the so-called texturing operation, for the purpose of improving magnetic head fly characteristics through reduction of frictions and at the same time for improving magnetic orientation of the storage medium coated on the disk surface.
In texturing operations of this nature, combinations of a texturing tape or tapes and abrasive particles have been widely resorted to as means for abrading disk surfaces. Abrasive particles are either deposited on a texturing tape or dispersed in and fed by an abrasive carrier liquid. For instance, in a texturing operation using an abrasive carrier liquid containing abrasive particles in dispersed state, a disk is mounted on a spindle for rotation therewith, and the abrasive carrier liquid is fed to between the texturing surface of the rotating disk and the texturing tape which is pressed against the disk surface under a predetermined load. While rotating the disk on the spindle, the texturing tape is transported along and across the rotating disk surface with the abrasive particles of the abrasive carrier liquid in pressed contact with the disk surface. As a result, the disk surface is textured with circumferential grooves by scratching or abrading actions of the abrasive particles.
When a texturing tape is simply transported across the surface of a rotating disk, the disk surface is textured with circumferential grooves lying concentrically around the center of the disk. In this connection, texturing with cross-pattern grooves is proposed U.S. Pat. No. 4,973,496, forming intersecting grooves on the disk surface for replenishment of a lubricant which is generally applied on the textured disk surface in a subsequent stage. According to the just-mentioned U.S. patent, the texture of cross-pattern grooves is advantageous especially from the standpoint of magnetic head lift characteristics because, even if a lubricant should wear off in certain localities of the disk surface, it can be replenished from other regions through intersections of the cross-pattern grooves, constantly maintaining a uniform lubricant film all over the disk surface.
In order to form cross-pattern grooves, it has been required to move the texturing tape back and forth along the texturing disk surface and in radial directions of the disk, in addition to the rotation of the disk and the transport of the texturing tape. For this purpose, the above-mentioned prior art U.S. patent employs a tape transport mechanism having a roller for pressing the texturing tape against the disk surface and mounted on an oscillating frame structure which is driven by a motor for reciprocating movements in radial directions parallel with the disk surface. In this case, however, there always arises a problem that, as the frame structure is moved back and forth parallel with the disk surface, the disk is shaken or vibrated under the influence of inertial forces at the stroke ends of the oscillating frame structure depending upon the mass of the roller or other component parts which are mounted on the oscillating frame structure, as a result disturbing the uniformity of texture grooves to be formed on the disk. The inertial forces at the stroke ends become greater and the vibrations of the disk are magnified to such a degree as to jeopardize formation of uniform texture grooves especially in case the rotational speed of the disk and the speed of reciprocating movement of the roller are increased for the purpose of accelerating the texturing operation.